In a conventional image processing apparatus, a correcting process similar to that for the other region has been executed to a skin region in an image. Therefore, an adverse affect from the viewpoint of image quality is given to the skin portion of a person in the image. For example, when a correction for emphasizing an outline is executed as an image process, defect such as spots, wrinkles, breakouts, or the like on a face in the image becomes noticeable. Further, when a backlight process is executed as an image process, the face in the image becomes brighter or darker, which appears odd compared to the other portions. A region of a skin of a person in an image is referred to as a “skin region” hereinbelow.
There is Patent Document 1 or Patent Document 2 as a conventional technique for solving the aforesaid problem. In the techniques disclosed in these documents, a skin region in an image is detected, wherein an amount of correction is reduced to the skin region. Thus, an adverse affect from the viewpoint of image quality to the skin region is suppressed.
Specifically, in the technique disclosed in the Patent Document 1, when detecting the skin region, an image is represented by a brightness and color difference, and a skin color level is obtained by using the color difference so as to specify the region having the high skin color level as a skin region. The image is represented by Y (brightness), Cb (color difference), and Cr (color difference), wherein the difference between Cb and Cr, which are central in a skin color, is employed as a skin color level. In the technique disclosed in the Patent Document 2, an image is represented by Y, H, and C, wherein a skin region is specified by using H (color phase), and C (color saturation).    Patent Document 1: Japanese Patent Application Laid-Open No. 2005-341527    Patent Document 2: Japanese Patent Application Laid-Open No. 2004-173328